Developing management guidelines for cerulean warbler breeding habitatThis article is part of a larger document. View the larger document here.
Recovery activities for species of conservation concern may be directed to acquire and protect habitats known to contain the species, or to produce suitable habitats or locations suspected to be capable of supporting populations of the species. Management of those habitats ultimately becomes necessary, especially where production of additional habitats is deemed necessary. The Cerulean Warbler Technical Group (CWTG) is working to maintain current Cerulean Warbler (Dendroica cerulea (Wilson), Aves: Parulidae) populations and ultimately to double them within the Partners in Flight North American Conservation Plan. This species’ population has declined as much as 70 percent since 1965, as measured by our only rangewide yardstick of breeding distribution and trends, the Breeding Bird Survey. These birds were listed as Vulnerable in the prestigious Threatened Birds of the World in 2004. Previously a candidate species under provisions of the U.S. Endangered Species Act (ESA), a petition to list them as Threatened under ESA was lodged in 2000. Ongoing CWTG research activities address three fronts in development of guidelines for habitat management: response of breeding populations to controlled manipulations of existing stands for vegetation management, distribution of the birds among Society of American Foresters’ Forest Cover Types, and suggestion of specific practices to improve habitat suitability of particular stands. These practices will vary geographically throughout the species’ range, but will focus on common structural elements (e.g., patchy emergent tree canopies) that occur in a variety of forest types. Work on breeding habitats indicates that silvicultural manipulation of the vegetation ultimately will become an important management tool for the species. The studies are, however, in their early stages, permitting us to suggest possible guidelines and illustrate possible objectives and potential consequences. We are not yet in position to specify outcomes of application of particular prescriptions with defined confidence limits.